Your blog is pretty interesting and makes some good points. Certainly there are karate-ka who are pretty bulky and they still seem to be able to perform karate very well. Some examples include:

Michael Jai White:

Jean-Claude Van Damme:

Dolph Lundgren:

Note I said perform karate, as in demonstrate certain karate moves in a choreographed way. How these guys would fair in sparring matches I'm unsure about.

In terms of sports performance, an athlete should do strength and conditioning that assists their performance. Their primary focus won't really be how they look. Someone like Fedor Emelianenko may not look like Lou Ferrigno, but he is a highly fit and effective combat athlete.

If I were interested in improving my karate, I would look in to various strength and condition exercises to help performance and prevent injury.

In regards to power generation for blocking and striking, excellent body mechanics wins the day. There is no point in weighing 200 lbs if you have poor body mechanics and can't generate a lot of force.

As to why grapplers have thicker/heavier bodies, well, in my experience heavier people are harder to move. Simple as that. Generally speaking heavier people usually have an advantage in grappling.

This's a wide open question. There are many factors that would influence what type of body one wanted. Are you fighting self-defense?Sport Karate?....The list goes on and on. Let's try self-defense. Do you want go with the old stereotypes..Big and strong/Goju, or Quick and fast Shorin?(I don't believe in the old big-Goju,fast-Shorin line.) I don't think there's a ideal Karate body. I think that the topic has too many variables. It does give one food for thought though. Having thought about it I have decided that my ideal Karate body will always be about 15 lbs less than whatever my current weight is at that time.Oh well.

Grapplers are ''thick'' because grappling requires lots of physical power and training grappling with a partner easily provides enough muscle stimulation to make you grow ''thicker''.

Anyway I don't see what your question really is.. If it's asthetics then I don't know since I don't care about them and don't think any need to exist in martial arts - at least not in the forms most see them in.

In terms of functionality our bodies and body types are different, muscle gains and such are affected by how we train and how we train is affected by what we're training for. I could go on a long long rant BUT in the end of the day to summarize; the main thing to any martial art is body mechanics without good body mechanics power & speed are lost. You can be ''bulked up'' and do good karate provided you have good body mechanics and vice versa be skinny and perform well.

So it doesn't matter if you train in the right way focused on your goals and requirements your body will be what it needs to be.

In a good karate-body i aim for stamina. If i've pushed myself through a hard session and survived with a smile on my face at the end, then i can feel assured that i'm getting out of my training what i am putting in. A good Karate-body in my opinion is not one that is good looking, but one that is good serving.

I've been told I got an excellent body for Judo, but I practice karate. I'm 116kg at 178cm.

I always teach my students that a good style and karateka will mold their karate around them NOT mold them around the Karate.

What you find is that Karate is an Aerobic exercise whereas to build Muscle form etc requires Anerobic exercise. they go against each other. another Aerobic exercise is Running, I've never met a Bulky Long Distance Runner and Short Distance runners tend to be bulkier is statue.

Take Football (soccer for non-Europeans) comapred to Rugby/American Football. there are size differences there too.